Work will continue on the membrane receptor(s) for endotoxin on human platelets and on the platelet membrane receptor for immune complexes. The structure-function relationship among different forms of bacterial endotoxin in terms of their interaction with the human platelet membrane will be investigated. We will characterize further the human platelet component which interacts with immune complexes and compare it with endotoxin receptor. The third line of investigation will concern further characterization of human fibrinogen binding sites for staphylococci. BIBLIOGRAPHIC REFERENCES: Hawiger, J.: Disseminated intravascular coagulation in patients with infections: diagnostic and therapeutic approach. Materia Med. Pol. 27:1, 1976. Hawiger, J., Hawiger, A., Steckley, S., Timmons, S., and Cheng, C.: Membrane changes in human platelets induced by lipopolysaccharide endotoxin. Brit. J. Haemat. 35:285, 1977.